The present invention relates to semiconductor components. More specifically, the semiconductor components relate to so-called compensation components having a drift zone which, adjacent to one another, have in each case complementarily doped semiconductor zones that mutually deplete one another in the off-state case, and to semiconductor components having a drift zone of only one conduction type.
Semiconductor components having a drift zone which have a compensation structure are sufficiently known and described for example in U.S. Pat. No. 4,754,310 or U.S. Pat. No. 6,097,063.
What is critical for the properties of the drift zone in the off-state case of the component is, in particular, the degree of compensation, as is explained thoroughly in DE 198 40 032 C1. The degree of compensation K is defined for n-conducting components asK=(Nn−Np)/Nn  (1)and is defined for p-conducting components asK=(Np−Nn)/Np,  (2)where Nn specifies the number of n-type dopant atoms and Np specifies the number of p-type dopant atoms in a volume region considered.
When considered over the entire volume, the degree of compensation is preferably zero. The number of p-type dopant atoms corresponds to the number of p-type dopant atom, so that, in the off-state case, each free n-type charge carrier finds a free p-type charge carrier, which mutually compensate for one another, as a result of which free charge carriers are no longer present in the drift zone at maximum reverse voltage.
The above-mentioned DE 198 40 032 C1 proposes varying the degree of compensation along a current flow direction in the drift zone in order to achieve a high breakdown strength and a high current-carrying capacity before or at breakdown. In this case, the doping is effected in such a way that p-type charge carriers predominate in a first region of the drift zone, which first region adjoins a pn junction between a p-doped semiconductor zone and n-doped regions of the drift zone, as a result of which the degree of compensation is negative there, while in a region near to a second semiconductor zone, n-type charge carriers predominate in the drift zone. In a third region of the drift zone between the first and second semiconductor zones, the degree of compensation is preferably zero, that is to say the complementarily doped semiconductor zones which are in each case arranged adjacent there completely compensate for one another in the off-state case.